汽车构造英文版Word格式文档下载.docx

1、Transmission systems conveys the drive to the wheels. The main components are clutch, gearbox, driveshaft, final drive, and differential.Suspension absorbs the road shocks.Steering controls the direction of the movement.Brake slows down the vehicle.1.5 Electrical EquipmentThe electrical system suppl

2、ies electricity for the ignition, horn, lights, heater, and starter. The electricity level is maintained by a charging circuit. This circuit consists of the battery, alternator （or generator）. The battery stores electricity. The alternator changes the engines mechanical energy into electrical energy

3、 and recharges the battery.New WordsPrincipal component 主要部件category 种类，类型body 车身chassis 底盘layout 布置power unit 动力装置internal combustion engine 内燃机cylinder 汽缸gasoline 汽油spark 火花ignition 点燃，点火diesel 柴油机compression 压缩shaft 轴transmission 传动系sheet metal 金属板shell 外壳hood （发动机）罩trunk deck 行李舱盖cargo 货物styling

4、 样式assembly 总成，装配suspension 悬挂，悬置shock 冲击steering 转向，操纵brake 刹车，制动器clutch 离合器gearbox 变速器driveshaft 传动轴final drive 主减速器，后桥differential 差速器slow down （使）慢下来，减速horn 喇叭starter 起动机charge 充电alternator 交流发电机Review Questions 1. List the main parts of an automobile?2. What are the common types of a vehicle ac

5、cording to body styling?3. Which systems does a chassis include and what are the main functions of the chassis?4. Why are suspension systems used on vehicles?CHAPTER2 INTERNAL COMBUSTION ENGINE2.1 principle of operation 2.1.1 Engine and power Engine is used to produce power. The chemical energy in f

6、uel is converted to heat by the burning of the fuel at a controlled rate. This process is called combustion. If engine combustion occurs with the power chamber. ,the engine is called internal combustion engine. If combustion takes place outside the cylinder, the engine is called an external combusti

7、on engine. Engine used in automobiles are internal combustion heat engines. Heat energy released in the combustion chamber raises the temperature of the combustion gases with the chamber. The increase in gas temperature causes the pressure of the gases to increase. The pressure developed within the

8、combustion chamber is applied to the head of a piston to produce a usable mechanical force, which is then converted into useful mechanical power.2.1.2 Engine Terms Linking the piston by a connecting rod to a crankshaft causes the gas to rotate the shaft through half a turn. The power stroke “uses up

9、” the gas , so means must be provided to expel the burnt gas and recharge the cylinder with a fresh petrol-air mixture :this control of gas movement is the duty of the valves ;an inlet valve allows the new mixture to enter at the right time and an exhaust valve lets out the burnt gas after the gas h

10、as done its job. Engine terms are : TDC（Top Dead Center）:the position of the crank and piston when the piston is farther away from the crankshaft. BDC（Bottom Dead Center）:the position of the crank and piston when the piston is nearest to the crankshaft. Stroke : the distance between BDC and TDC; str

11、oke is controlled by the crankshaft. Bore : the internal diameter of the cylinder. Swept volume : the volume between TDC and BDC. Engine capacity : this is the swept volume of all the cylinder e.g. a four-stroke having a capacity of two liters（2000cm） has a cylinder swept volume of 50cm. Clearance v

12、olume: the volume of the space above the piston when it is at TDC. Compression ratio = （swept vol + clearance vol）（clearance vol） Two-stroke : a power stroke every revolution of the crank. Four-stroke : a power stroke every other revolution of the crank.2.1.3 The Four-stroke Spark-ignition Engine Cy

13、cle The spark-ignition engine is an internal-combustion engine with externally supplied in ignition , which converts the energy contained in the fuel to kinetic energy. The cycle of operations is spread over four piston strokes. To complete the full cycle it takes two revolutions of the crankshaft.T

14、he operating strokes are : This stroke introduces a mixture of atomized gasoline and air into the cylinder. The stroke starts when the piston moves downward from a position near the top of the cylinder. As the piston moves downward, a vacuum, or low-pressure area, is created. During the intake strok

15、e, one of the ports is opened by moving the inlet valve. The exhaust valve remains tightly closed.Compression strokeAs the piston moves upward to compress the fuel mixture trapped in the cylinder, the valves are closed tightly. This compression action heats the air/fuel mixture slightly and confines

16、 it within a small area called the combustion chamber.Power strokeJust before the piston reaches the top of its compression stroke, an electrical spark is introduced from a spark plug screwed into the cylinder head.The spark ignites the compressed, heated mixture of fuel and air in the combustion ch

17、amber to cause rapid burning. The burning fuel produces intense heat that causes rapid expansion of the gases compressed within the cylinder. This pressure forces the piston downward. The downward stroke turns the crankshaft with great force.Exhaust strokeJust before the bottom of the power stroke,

18、the exhaust valve opens. This allows the piston, as it moves upward, to push the hot, burned gases out through the open exhaust valve.Then, just before the piston reaches its highest point, the exhaust valve closes and the inlet valve opens. As the piston reaches the highest point in the cylinder, k

19、nown as TDC, it starts back down again. Thus, one cycle ends and another begins immediately.2.1.4 Engine Overall Mechanics The engine has hundreds of other parts . The major parts of engine are engine block , engine heads, pistons, connecting rods, crankshaft and valves. The other parts are joined t

20、o make systems. These systems are the fuel system, intake system, ignition system, cooling system, lubrication system and exhaust system. Each of these systems has a definite function. These systems will discussed in detail later. NEW WORDPiston 活塞Connecting rod 连杆Crankshaft 曲轴Power stoke 活塞行程Expel

21、排出Valve 气阀inlet（intake） valve 进气阀exhaust valve 排气阀term 术语TDC 上止点BDC 下止点Bore 缸径swept volume 有效容积engine capacity 发动机排量clearance volume 余隙容积,燃烧室容积compression ratio 压缩比revolution 旋转,转数every other 每隔一个cycle 循环spread over 分布,遍及intake stroke 进气行程 compression stroke 压缩行程knock 敲缸,敲打exhaust stroke 排气行程engine

22、block 发动机缸体lubrication 润滑2.2 Engine Block and Cylinder Head2.2.1 Engine BlockThe engine block is the basic frame of the engine. All other engine parts either fit inside it or fasten to it. It holds the cylinders, water jackets, and oil galleries. The engine block also holds the crankshaft, which fas

23、tens to the bottom of the block. The camshaft also fits inside the block, except on overhead-cam engines （OHC）. In most cars, this block is made of gray iron, or an alloy （mixture） of gray iron and other metals, such as nickel or chromium. Engine blocks are castings.Some engine blocks, especially th

24、ose in smaller cars, are made of cast aluminum. This metal is much lighter than iron. However, iron wears better than aluminum. Therefore, the cylinders in most aluminum engines are lined with iron or steel sleeves. These sleeves are called cylinder sleeves. Some engine blocks are made entirely of a

25、luminum.2.2.2 Cylinder HeadThe cylinder head fastens to the top of the block, just as a roof fits over a house. The underside forms the combustion chamber with the top of the piston. The most common cylinder head types are the hemi, wedge, and semi-hemi. All three of these terms refer to the shape o

26、f the engines combustion chamber. The cylinder head carries the valves, valve springs and the rockers on the rocker shaft, this part of the valve gear being worked by the push-rods. Sometimes the camshaft is fitted directly into the cylinder head and operates on the valves without rockers. This is c

27、alled an overhead camshaft arrangement. Like the cylinder block, the head is made from either cast iron or aluminum alloy.2.2.3 GasketThe cylinder head is attached to the block with high-tensile steel studs. The joint between the block and the head must be gas-tight so that none of the burning mixture can escape. This is achieved by using cylinder head gasket. This is a sandwich gasket, i.e. a sheet of asbestos between two sheets of copper, both these materials being able to withstand the high temperature and pressures within the engine